Pipe protector with perforated metal sheet insert

ABSTRACT

A well pipe protector of split construction includes an elastomer body and a core in the form of a metal sheet embedded in the body, the sheet containing rows of through perforations which are elongated in the direction of the body axis, and the perforations in adjacent rows being staggered.

United States Patent Hoon et al. July 15, 1975 [54] PIPE PROTECTOR WITH PERFORATED 1,965,730 7/1934 Williams 308/4 A METAL SHEET INSERT 1,965,998 7/1934 Williams 308/4 A 3,425,757 2/1969 Miner 308/4 A 1 Inventors: Howard 0 een, Sa a Momca; 3,449,022 6/1969 Miner 308/4 A Fernando Murman, Palos Verdes 3,592,515 7/1971 Gram 308/4 A Peninsula, both of Calif, 3,612,627 10/1971 Fuller 308/4 A H [73] Asslgnee 33? Company Los Angeles Przmary Examzner-Charles J. Myhre Assistant ExaminerR. H. Lazarus [22] Filed: Sept. 13, 1973 Attorney, Agent, or Firm-William W. Haefliger [21] Appl. No.: 396,895

[57] ABSTRACT [52] US. Cl 308/4 A A pipe protector of Split construction includes an 51 Int. Cl. F16C 17/00 elastomef W and a We in the form Ofa metal Sheet [58] Field 61 Search 308/4 A embedded in the body the Sheet maining rows through perforations which are elongated in the direc- [56] References Cited tion of the body axis, and the perforations in adjacent UNITED STATES PATENTS mws bemg Staggered 1,913,018 6/1933 Berryman 308/4 A 10 Claims, 10 Drawing Figures PIPE PROTECTOR WITH PERFQRATED METAL SHEET INSERT BACKGROUND OF THE INVENTION This invention relates generally to well pipe protection, and more particularly concerns simplifications in protector body and core construction and also facilitat ing protector usage in corrosive fluid environments.

In the past, well pipe protectors embodying metal cores or inserts have lacked the simple, stretchable core and all-elastomer body construction characterized by the present invention; as a result they have lacked the combinations of unusual advantages in structure, mode of operation and results as will be described in detail herein, and which overcome problems encuntered in prior protector design. Among the latter are excessive complexity, slippage along the pipe to which protectors are clamped, and excessive degradation, wear and deterioration when rotated with pipe in a well bore.

SUMMARY OF THE INVENTION The invention basically embedded in an improved well pipe protector comprising a C-shaped unit sized to fit laterally about axially elongated well pipe, and including an elastomer body and a core in the form of a metal sheet embedded in the body; terminals on the unit to be drawn together in interfitting relation for retention after lateral application of the body about a well pipe; the metallic sheet containing rows of through perforations, the rows extending in the general direction of the pipe axis with perforations in each row spaced apart in that direction, the perforations in adja cent rows being staggered; and the perforations in each row being elongated in the general direction of the pipe and protector axes. As will be seen, the terminals include metallic loops integral with the sheet and embedded in the body terminals for protection against corrosion, the loops and body terminals defining openings to receive a retainer pin.

With respect to the perforations, in one form of the invention they define axially elongated slots, and axially elongated flexible metal bars formed between adjacent rows of slots; and in another form of the invention the perforations have axially elongated diamond shaped configuration with the metal bars extending linearly and angularly in relation to the pipe and protector axes. In all forms of the invention, the elastomer body material extends through the perforations for creating multiple clamping force pressure points, and to aid in interconnecting the rubber and core sheet.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION FIG. 1 is a side elevation of a pipe protector assembled on well pipe;

FIG. 2 is a section taken on lines 2-2 of FIG. 1;

FIG. 3 is a perspective showing of the FIG. 1 protec tor prior to assembly without the pipe;

FIGS. 4 and 5 are enlarged fragmentary sections through the protector;

FIG. 6 is a side elevation of a metallic core employed in the FIGS. 1-5 protector;

FIG. 7 is a top plan view of the core, in bowed condition;

FIGS. 8 and 9 are fragmentary elevation showing modified cores; and

FIG. 10 is a fragmentary showing of a modification.

DETAILED DESCRIPTION In FIGS. 1 and 2 the protector in the form of a C- shaped unit 10, applied for example to axially elongated drill pipe 11, has an elastomer (as for example rubber) body 12 in which is embedded thin metallic (as for example spring steel) core 13. The body 12 may be internally longitudinally ribbed at and between annular lands 14 at the ends of body bore, for compressive engagement with the drill pipe, so as to frictionally resist travel lengthwise of the pipe. Alternatively, the ribs may be omitted and the body bore may be smooth. As to the latter, FIG. 10 shows a rubber body 112 in which a core 113 is embedded. The body has a smooth annular bore at 114, and the core may be similar to core 13.

It will be seen that the protector has terminals adapted to be drawn together in interfitting relation, for retention after lateral application of the body and core about the pipe 11. In this regard, the terminals may, with unusual advantage, be defined by first and second groups 16 and 17 of staggered teeth 16a and 17a formed by the body 12. Such teeth have longitudinal openings 16b and 17b therein adapted to be brought into alignment to receive a corrosion resistant retainer pin 18 upon coupling the protector about the pipe. Such alignment may be affected by manipulation of tongs, the jaws 20 and 21 of which are receivable into openings 22 and 23 formed in body 12, near the teeth.

To facilitate application of the protector 10 about pipe 11, the core 13 is resiliently expandable in the direction of arrows 24 in FIG. 2, and from the untensioned positioned of FIG. 3 in which teeth 16 and 17 are out of alignment to provide a gap 25 thcrebetween. In other words, the gap or slit 25 is widened to pass the pipe 11.

The elastomeric body extent 12a at the inner side of the core 13 is adapted to be compressed between the core and pipe when the protector is coupled to the pipe with terminals 16 and 17 being drawn together and interconnected, as is clear from FIG. 5. The body material fills the perforations formed by the core, and may overlie the core at the inner side thereof for aid in interconnecting the core and body, in the FIGS. 2 and 3 example. The vertical gaps between ribs 120 are signified at 12b. Coupling of the protector to the pipe squeezes the body 12 from the condition seen in FIG. 4 to that seen in FIG. 5, for example, with rubber being squeezed into the inter-rib openings 12b. Such coupling firmly attaches the protector to the pipe, there being no exposed metal grips required. Ribs 12a may occur randomly relative to the perforations in the core sheet 13.

Referring to FIG. 6, the resiliently stretchable core sheet 13 is seen to contain vertical rows of like perforations 30 extending in the direction of the pipe or protector axis 31, and the perforations in each row being spaced apart in that direction and by narrow metallic webs 32. Further, the perforations in circumferentially adjacent rows are circumferentially staggered, and the perforations in each row are elongated in the direction of axis 31, forming elongated slots with the length dimension of each slot being at least twice its width dimension. As a result, the sheet defines narrow metal bars or beams 33 between the perforations, the bars being axially elongated and flexible, with widths less than slot width, the bars being circumferentially interconnected by the webs 32. For a typical protector, the number of bars and slots and their dimensions should be such that total circumferential stretch of the core 13 is between about 0.175 and 0.250 inches. Typically, the core sheet 13 may consist of heat treated alloy steel of up to about 0.08 inch thickness.

The large number of slots assures that the molded rubber body sections inside and outside the core will have extensive interconnection, aiding interconnecting of the core to the body and accommodating flow of rubber through the perforations; also a large number of radial pressure points will result, to better distribute the clamping force about the entire inner diameter of the protector. Further, the protector will locally deflect to out-of-round condition, as required, to accommodate to out-of-round pipe extent. The sum of the areas of the perforations is about one-half the total area of the perforated sheet extent.

FIG. 7 shows metal loops 36 and 37 rivet connected at 38 to turned end portions 39 of the core sheet 13. As seen in FIG. 2, such structure is embedded in the molded rubber body teeth, to receive the pin 18 through openings 36a and 37a formed by the loops. Loops 36 are molded in rubber teeth 16a, and loops 37 in rubber teeth 17a.

FIG. 8 shows another form of core sheet 40 having diamond shaped perforations 41, also with elongation in the axial direction 42. Linearly elongated, flexible metal bars, of narrow, substantially uniform width are formed at 43, and at 43a, at opposite sides of the perforations. Bars 43 extend at an angle a from vertical, and bars 43a extend at an angle a from vertical. The configuration in FIG. 9 is similar to that of FIG. 8, but the bars 43b and 43s are wider, and do not extend linearly between the top and bottom edges of the core sheet, but are rather interrupted by the diamond shaped slots 4141. Also, circumferential webs 45 interconnect the bars at the top and bottom of the sheet.

Another advantage consists in the fact that, due to the slight overall thickness of the insert, maximum wearable rubber thickness exists outwardly of the insert, for a protector body of given overall thickness and given rubber thickness inwardly of the insert, so that wear life is maximized. In this regard, the protector exterior is subject to severe frictional wear due to sliding and rotating engagement with the well bore, as for example is defined by well casing.

From the above, it is clear that the bars will flex and the core sheet will resiliently stretch circumferentially to limited extent as the terminals or teeth 16 and 17, or loops 36 and 37, are drawn together after lateral application of the protector body about a pipe.

I claim:

1. In a well pipe protector,

a. a C-shaped unit sized to fit laterally about axially elongated well pipe, and including an elastomer body and a core in the form of a metallic sheet embedded in the body,

b. terminals on the unit to be drawn together in interfitting relation for retention after lateral application of the body about a pipe, and

c. the metallic sheet containing rows of through perforations characterized in that the sheet is made resiliently stretchable when the unit is applied about the well pipe, the rows extending in the general direction of said axis, the perforations in each row being spaced apart in said direction, the perforations in all circumferentially adjacent rows being staggered, and

d. the perforations in each row being elongated in the general direction of said axis and defining axially elongated slots, the slot length dimensions exceeding the slot width dimensions, the sheet defining axially elongated flexible metal bars between adjacent rows of slots, the bars having minimum widths less than the slot widths, there being webs formed between slots in each row, the webs interconnecting the bars, the web minimum dimensions in an axial direction being less than the slot widths, whereby the bars will flex and the core sheet will resiliently stretch circumferentially to limited extent as said terminals are forcibly drawn together after said lateral application of the body about a pipe.

2. The protector of claim 1 wherein the terminals include metallic loops integral with the sheet and embedded in elastomer terminals defined by the body, the metallic loops and elastomer terminals defining openings to receive a retainer pin.

3. The protector of claim 1 wherein the length dimension of each slot is at least twice the slot width dimension.

4. The protector of claim 3 wherein elastomer body material projects through said slots.

5. The protector of claim 1 wherein the bars extending in straight paths between the top and bottom edges of the sheet.

6. The protector of claim 1 wherein the sum of the areas of the slots is about half the total area of the sheet slotted extent.

7. The protector of claim 1 wherein body elastomer material substantially fills the perforations.

8. In a well pipe protector,

a. a C-shaped unit sized to fit laterally about axially elongated well pipe, and including an elastomer body and a core in the form of a metallic sheet embedded in the body,

b. terminals on the unit to be drawn together in interfitting relation for retention after lateral application of the body about a pipe, and

e. the metallic sheet containing rows of'through perforations characterized in that the sheet is made resiliently stretchable when the unit is applied about the Well pipe, the rows extending in the general direction of said axis, the perforations in each row being spaced apart in said direction, the perforations in circumferentially adjacent rows being staggered, and the perforations in each row being elongated in the general direction of said axis and having diamond configuration with elongation in the general direction of said axis, the sheet defining linearly elongated flexible metal bars of substantially uniform width extending at opposite sides of the perforations and angularly with respect to said axis, the bars having widths which are less than the maximum widths of the diamond shaped perforations, the bars at laterally opposite sides of the perforamaterial projects through said perforations.

10. The protector of claim 2 clamped on a pipe with said terminals held in drawn together relation by a pin received through aligned terminal openings and metallic loops as defined. 

1. In a well pipe protector, a. a C-shaped unit sized to fit laterally about axially elongated well pipe, and including an elastomer body and a core in the form of a metallic sheet embedded in the body, b. terminals on the unit to be drawn together in interfitting relation for retention after lateral application of the body about a pipe, and c. the metallic sheet containing rows of through perforations characterized in that the sheet is made resiliently stretchable when the unit is applied about the well pipe, the rows extending in the general direction of said axis, the perforations in each row being spaced apart in said direction, the perforations in all circumferentially adjacent rows being staggered, and d. the perforations in each row being elongated in the general direction of said axis and defining axially elongated slots, the slot length dimensions exceeding the slot width dimensions, the sheet defining axially elongated flexible metal bars between adjacent rows of slots, the bars having minimum widths less than the slot widths, there being webs formed between slots in each row, the webs interconnecting the bars, the web minimum dimensions in an axial direction being less than the slot widths, whereby the bars will flex and the core sheet will resiliently stretch circumferentially to limited extent as said terminals are forcibly drawn together after said lateral application of the body about a pipe.
 2. The protector of claim 1 wherein the tErminals include metallic loops integral with the sheet and embedded in elastomer terminals defined by the body, the metallic loops and elastomer terminals defining openings to receive a retainer pin.
 3. The protector of claim 1 wherein the length dimension of each slot is at least twice the slot width dimension.
 4. The protector of claim 3 wherein elastomer body material projects through said slots.
 5. The protector of claim 1 wherein the bars extending in straight paths between the top and bottom edges of the sheet.
 6. The protector of claim 1 wherein the sum of the areas of the slots is about half the total area of the sheet slotted extent.
 7. The protector of claim 1 wherein body elastomer material substantially fills the perforations.
 8. In a well pipe protector, a. a C-shaped unit sized to fit laterally about axially elongated well pipe, and including an elastomer body and a core in the form of a metallic sheet embedded in the body, b. terminals on the unit to be drawn together in interfitting relation for retention after lateral application of the body about a pipe, and c. the metallic sheet containing rows of through perforations characterized in that the sheet is made resiliently stretchable when the unit is applied about the well pipe, the rows extending in the general direction of said axis, the perforations in each row being spaced apart in said direction, the perforations in circumferentially adjacent rows being staggered, and d. the perforations in each row being elongated in the general direction of said axis and having diamond configuration with elongation in the general direction of said axis, the sheet defining linearly elongated flexible metal bars of substantially uniform width extending at opposite sides of the perforations and angularly with respect to said axis, the bars having widths which are less than the maximum widths of the diamond shaped perforations, the bars at laterally opposite sides of the perforations intersecting at junctions between longitudinally spaced perforations, whereby the bars will flex and the core sheet will resiliently stretch circumferentially to limited extent as said terminals are forcibly drawn together after said lateral application of the body about a pipe.
 9. The protector of claim 8 wherein elastomer body material projects through said perforations.
 10. The protector of claim 2 clamped on a pipe with said terminals held in drawn together relation by a pin received through aligned terminal openings and metallic loops as defined. 